CVE-2021-24176 in JH 404 Logger Plugin
Summary
by MITRE • 04/06/2021
The JH 404 Logger WordPress plugin through 1.1 doesn't sanitise the referer and path of 404 pages, when they are output in the dashboard, which leads to executing arbitrary JavaScript code in the WordPress dashboard.
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Analysis
by VulDB Data Team • 04/10/2021
The CVE-2021-24176 vulnerability affects the JH 404 Logger WordPress plugin version 1.1 and earlier, presenting a critical security flaw that enables persistent cross-site scripting attacks within the WordPress administrative interface. This vulnerability arises from insufficient input sanitization mechanisms within the plugin's handling of 404 error page data, specifically targeting the referer and path parameters that are displayed in the WordPress dashboard. The flaw allows attackers to inject malicious JavaScript code through crafted 404 error entries that are subsequently rendered in the admin interface without proper sanitization.
The technical exploitation of this vulnerability occurs when an attacker crafts a malicious referer or path string containing JavaScript payload that gets stored in the plugin's database as part of the 404 error logging process. When administrators view the 404 error logs within the WordPress dashboard, the unsanitized input is executed in the context of the administrator's browser session, creating a persistent cross-site scripting vector. This vulnerability directly maps to CWE-79 - Improper Neutralization of Input During Web Page Generation, which specifically addresses the failure to sanitize user-controllable data before including it in web pages. The attack vector leverages the principle of stored cross-site scripting where malicious code is stored on the server and executed when victims access the affected page.
The operational impact of CVE-2021-24176 extends beyond simple script execution, as it provides attackers with a foothold for more sophisticated attacks within the WordPress environment. Administrators who view the 404 error logs become victims of the stored XSS, potentially allowing attackers to steal session cookies, perform actions on behalf of administrators, or redirect them to malicious sites. This vulnerability can be particularly dangerous in environments where administrators frequently check error logs, as it creates a consistent attack surface that persists until the vulnerability is patched. The attack aligns with ATT&CK technique T1566.001 - Phishing: Spearphishing Attachment, where the malicious payload is delivered through the legitimate administrative interface rather than external phishing campaigns.
Mitigation strategies for this vulnerability should include immediate patching of the JH 404 Logger plugin to version 1.2 or later, which contains the necessary input sanitization fixes. Organizations should also implement additional security measures such as regular monitoring of plugin updates, implementing Content Security Policy headers to limit script execution, and conducting security audits of installed plugins to identify similar sanitization flaws. Network segmentation and role-based access controls can help limit the potential damage if an attacker successfully exploits this vulnerability, while regular security scanning of the WordPress installation can help identify other plugins with similar issues. The vulnerability demonstrates the importance of input validation and output sanitization in web applications, particularly within administrative interfaces where elevated privileges exist and the potential for damage is significantly greater than in user-facing components.